A brave attempt to convey in simple terms some very complex physics. But a few points — the universe isn’t expanding at the speed of light but rather at 74kps per megaparsec. Secondly, according to current physics Alice won’t experience any changes when she crosses the event horizon (assuming we’ve insulated her from tidal effects) and won’t see the universe receding at the speed of light. Thirdly, there’s no correlation between the redshifting and heat from the evaporative effects of virtual particle pairs; the redshift is entirely due to the stretching of spacetime around the event horizon.

Just a few small points, but perhaps worth rectifying.